Magnetic storage devices are a key segment of information technology industries. Early tape drives and hard disk drives are examples of magnetic storage devices. For hard disk drives, the data density of written data bits on the magnetic medium has increased by a factor of more than two million since the first disk drive was applied to data storage. In addition, read/write data rates associated with read/write heads used in disk drives also continue to improve. While read heads can be scaled to smaller and smaller sensing areas, write head technology is becoming a road block to continued miniaturization.
A conventional write head includes a piece of ferrite wrapped in a coil. To write data, the coil is energized and a strong magnetic field forms in a gap between the write head and the magnetic media. The generated magnetic field magnetizes a portion of the magnetic media. To read the data, the read head is positioned above the magnetized portion and transforms the magnetic field into an electrical current. Although effective, conventional write heads limit the data density of written data bits on the magnetic medium. For instance, it becomes increasing difficult to magnetize only a desired portion of the magnetic media without inadvertently impacting adjacent portions as the size of the underlying portions becomes smaller and smaller. Conventional write heads also have complex shapes of ferrite to achieve the magnetic field requirement.
One additional area being explored for write head improvements is heat assisted magnetic recording (HAMR). HAMR magnetically records data on magnetic media using laser thermal assistance to first heat the magnetic media. With hard disk drives, HAMR requires a significant increase in complexity in the write heads with the integration of the laser and a plasmonic waveguide near field transducer to heat a very small area [˜20 nanometers (nm) across] of a magnetic media disk that is traveling at high speed (˜20 m/s) in a very short time to a relatively high temperature of about 400° C. It is difficult to achieve the required temperature gradients to allow writing to a small enough area. Accordingly, there is a need for a write head apparatus and method that overcomes the above described inadequacies and shortcomings.